Many liquids such as wine are susceptible to oxidation and should be protected against excessive oxidation to preserve its quality. When a bottle of table wine is opened and is only partially consumed, the portion remaining in the bottle deteriorates rapidly, even if the bottle is re-corked, because of oxidation by the oxygen that is present in the air.
A number of stopper devices are available to preserve the character of the remaining wine in the bottle that has been opened which are described, for example, in U.S. Pat. No. 4,763,803 to Schneider, U.S. Pat. No. 6,530,401 to Angehrn et al., and U.S. Pat. No. 6,874,545to Larimer et al. With these conventional devices, air is withdrawn from the bottle through elaborate channels within the stopper which are then sealed. A separate pump mechanism, which is temporarily coupled to the stopper, removes air from the bottle. These prior art devices tend to be complicated and expensive.